Seizure Clusters Research Articles

Acute subdural hematoma in an infant with a biphasic clinical course and late reduced diffusion

Background: Bright tree appearance (BTA) is a characteristic finding on diffusion-weighted magnetic resonance (MR) imaging with transient high intensity in the white matter. BTA is characteristic of infants with acute encephalopathy with biphasic seizures, but it has also been reported in head trauma cases. In this report, we describe an infant case of traumatic brain injury that demonstrated a biphasic clinical course and late reduced diffusion (TBIRD). Case Description: A 5-month-old boy suffered from head trauma and developed coma and seizures. Computed tomography scans revealed acute subdural hematoma on the right side. He underwent an emergency operation to remove the hematoma but subsequently had seizure clusters for three days. Diffusion-weighted MR imaging revealed BTA in the right cerebral hemisphere. He was treated with antiepileptic agents and fully recovered to pre-injury condition, and MR imaging no further revealed any BTA 20 days after head trauma. He developed no complications at the 10-month postoperative follow-up. Conclusion: We reported a case of TBIRD following head trauma in the infant. The pathogenesis remains unclear, but we consider the possibility of biphasic seizures in infant head trauma cases, and we should appropriately administer the anticonvulsants and carefully check for MR imaging.

Clinical characteristics and genetic analysis of pediatric patients with sodium channel gene mutation-related childhood epilepsy: a review of 94 patients.

This study aimed to examine the clinical and gene-mutation characteristics of pediatric patients with sodium channel gene mutation-related childhood epilepsy and to provide a basis for precision treatment and genetic counseling. The clinical data from 94 patients with sodium channel gene mutation-related childhood epilepsy who were treated at Hunan Children's Hospital from August 2012 to December 2022 were retrospectively evaluated, and the clinical characteristics, gene variants, treatment, and follow-up status were analyzed and summarized. Our 94 pediatric patients with sodium channel gene variant-related childhood epilepsy comprised 37 girls and 57 boys. The age of disease onset ranged from 1 day to 3 years. We observed seven different sodium channel gene variants, and 55, 14, 9, 6, 6, 2, and 2 patients had SCNlA, SCN2A, SCN8A, SCN9A, SCN1B, SCN11A, and SCN3A variants, respectively. We noted that 52 were reported variants and 42 were novel variants. Among all gene types, SCN1A, SCN2A, and SCN8A variants were associated with an earlier disease onset age. With the exception of the SCN1B, the other six genes were associated with clustering seizures. Except for variants SCN3A and SCN11A, some patients with other variants had status epilepticus (SE). The main diagnosis of children with SCN1A variants was Dravet syndrome (DS) (72.7%), whereas patients with SCN2A and SCN8A variants were mainly diagnosed with various types of epileptic encephalopathy, accounting for 85.7% (12 of 14) and 88.9% (8 of 9) respectively. A total of five cases of sudden unexpected death in epilepsy (SUDEP) occurred in patients with SCN1A, SCN2A, and SCN8A variants. The proportion of benign epilepsy in patients with SCN9A, SCN11A, and SCN1B variants was relatively high, and the epilepsy control rate was higher than the rate of other variant types. Sodium channel gene variants involve different epileptic syndromes, and the treatment responses also vary. We herein reported 42 novel variants, and we are also the first ever to report two patients with SCN11A variants, thereby increasing the gene spectrum and phenotypic profile of sodium channel dysfunction. We provide a basis for precision treatment and prognostic assessment.

Epilepsy phenotype and its reproducibility after lateral fluid percussion-induced traumatic brain injury in rats: Multicenter EpiBioS4Rx study project 1.

This study was undertaken to assess reproducibility of the epilepsy outcome and phenotype in a lateral fluid percussion model of posttraumatic epilepsy (PTE) across three study sites. A total of 525 adult male Sprague Dawley rats were randomized to lateral fluid percussion-induced brain injury (FPI) or sham operation. Of these, 264 were assigned to magnetic resonance imaging (MRI cohort, 43 sham, 221 traumatic brain injury [TBI]) and 261 to electrophysiological follow-up (EEG cohort, 41 sham, 220 TBI). A major effort was made to harmonize the rats, materials, equipment, procedures, and monitoring systems. On the 7th post-TBI month, rats were video-EEG monitored for epilepsy diagnosis. A total of 245 rats were video-EEG phenotyped for epilepsy on the 7th postinjury month (121 in MRI cohort, 124 in EEG cohort). In the whole cohort (n = 245), the prevalence of PTE in rats with TBI was 22%, being 27% in the MRI and 18% in the EEG cohort (p > .05). Prevalence of PTE did not differ between the three study sites (p > .05). The average seizure frequency was .317 ± .725 seizures/day at University of Eastern Finland (UEF; Finland), .085 ± .067 at Monash University (Monash; Australia), and .299 ± .266 at University of California, Los Angeles (UCLA; USA; p < .01 as compared to Monash). The average seizure duration did not differ between UEF (104 ± 48 s), Monash (90 ± 33 s), and UCLA (105 ± 473 s; p > .05). Of the 219 seizures, 53% occurred as part of a seizure cluster (≥3 seizures/24 h; p >.05 between the study sites). Of the 209 seizures, 56% occurred during lights-on period and 44% during lights-off period (p > .05 between the study sites). The PTE phenotype induced by lateral FPI is reproducible in a multicenter design. Our study supports the feasibility of performing preclinical multicenter trials in PTE to increase statistical power and experimental rigor to produce clinically translatable data to combat epileptogenesis after TBI.

Risk model of seizure cluster or status epilepticus and intervention in the emergency department

ObjectivesTo identify possible predictors of seizure cluster or status epilepticus (SE) and to evaluate whether these patients receive greater interventions in emergency departments. MethodologyWe conducted a secondary analysis of the ACESUR Registry, a multipurpose, observational, prospective, multicentre registry of adult patients with seizures from 18 emergency departments. Clinical and care-related variables were collected. We identified risk factors and risk models for seizure cluster or SE and assessed the effect of interventions by prehospital emergency services and the hospital emergency department. ResultsWe identified a total of 186 (28%) patients from the ACESUR registry with seizure cluster (126 [19%]) or SE (60 [9%]); the remaining 478 patients (72%) had isolated seizures. The risk model for seizure cluster or SE in the emergency department included Charlson Comorbidity Index scores ≥ 3 (OR: 1.60; 95% CI, 1.05–2.46; P=.030), ≥ 2 habitual antiepileptic drugs (OR: 2.29; 95% CI, 1.49–3.51; P<.001), and focal seizures (OR: 1.56; 95% CI, 1.05–2.32; P=.027). The area under the curve of the model was 0.735 (95% CI, 0.693–0.777; P=.021). Patients with seizure cluster and SE received more aggressive interventions both by prehospital emergency services (OR: 2.89; 95% CI, 1.91–4.36; P<.001) and at the emergency department (OR: 4.41; 95% CI, 2.69–7.22; P<.001). ConclusionsThis risk model may be of prognostic value in identifying adult patients at risk of presenting seizure cluster or SE in the emergency department. In our sample, these patients received more aggressive treatment than adult patients with isolated seizures before arriving at hospital, and even more so in the emergency department.

IBC-Oxford University2023_BJSPoster_17Bariatric Surgery on Patients with Epilepsy

Abstract Introduction Obesity is a common comorbid condition in patients with epilepsy, its occurrence is multifactorial and antiepileptic medications may contribute to the development of obesity and metabolic syndrome. Bariatric surgery can be offered to patients with epilepsy and obesity related comorbidities. Currently, there is lack of information regarding bariatric surgery on seizure control and antiepileptic drug concentration/toxicity. Methods A retrospective review of a local database was performed in a tertiary centre for Bariatric Surgery. All consecutive patients with epilepsy referred to the Bariatric MDT since 2010 were identified. Standard clinical data, postoperative complications, seizure frequency, antiepileptic therapy and weight loss were extracted. Results We identified 11 patients with epilepsy who underwent Bariatric Surgery (3 Sleeve gastrectomy, 4 gastric bypass, 4 gastric band). The %TWL 1 year after Bariatric Surgery (BS) was 22.4(20-24)%; 3 years following BS was 19.9(5-25)% and 5 years following BS was 18.9(4-24)%. 7 Patients remained seizure free during 5 year follow up after BS, in 3 people their seizure frequency did not change after BS and one patient had a cluster of dissociative seizures. There were no medication side effects reports due to impact of surgery. Conclusion Bariatric Surgery is a safe treatment option for individuals with epilepsy. The majority of patients with epilepsy who underwent bariatric surgery had no worsening in seizure frequency or experienced any medication side effects due to the impact of surgery on absorption. Individuals with morbid obesity and epilepsy can be considered for bariatric surgery. More research is required to adequately explore the impact of BS on patients with epilepsy.

Prevalence of nonconvulsive seizures and nonconvulsive status epilepticus in dogs and cats with a history of cluster seizures: A retrospective study.

Nonconvulsive seizures (NCS) and nonconvulsive status epilepticus (NCSE) are frequently observed in human patients. Diagnosis of NCS and NCSE only can be achieved by the use of electroencephalography (EEG). Electroencephalographic monitoring is rare in veterinary medicine and consequently there is limited data on frequency of NCS and NCSE. Determine the prevalence of NCS and NCSE in dogs and cats with a history of cluster seizures. Twenty-six dogs and 12 cats. Retrospective study. Medical records of dogs and cats with cluster seizures were reviewed. Electroencephalography was performed in order to identify electrographic seizure activity after the apparent cessation of convulsive seizure activity. Nonconvulsive seizures were detected in 9 dogs and 2 cats out of the 38 patients (29%). Nonconvulsive status epilepticus was detected in 4 dogs and 2 cats (16%). Five patients had both NCS and NCSE. A decreased level of consciousness was evident in 6/11 patients with NCS, 3/6 also had NCSE. Mortality rate for patients with NCS (73%) and NCSE (67%) was much higher than that for patients with no seizure activity on EEG (27%). Prevalence of NCS and NCSE is high in dogs and cats with a history of cluster seizures. Nonconvulsive seizures and NCSE are difficult to detect clinically and are associated with higher in hospital mortality rates. Results indicate that prompt EEG monitoring should be performed in dogs and cats with cluster seizures.

Adverse events of epidiolex: A real-world drug safety surveillance study based on the FDA adverse event reporting system (FAERS) database

Epidiolex, the first FDA-approved drug with cannabis extract, treats Dravet and Lennox-Gastaut syndromes. Using data from the FAERS database between 2018 and 2023, this study analyzed 13,275 Epidiolex-related adverse events. Through computational methods (ROR, PRR, BCPNN, EBGM), we found that real-world adverse reactions largely align with those in Epidiolex's drug leaflet. However, Seizure cluster, Blood ketone body decrease, Cortical visual impairment, Hyperactive pharyngeal reflex, and Poverty of speech emerged as potential new side effects not previously listed, warranting further attention for drug safety.

ACVIM Consensus Statement on the management of status epilepticus and cluster seizures in dogs and cats.

Seizure emergencies (ie, status epilepticus [SE] and cluster seizures [CS]), are common challenging disorders with complex pathophysiology, rapidly progressive drug-resistant and self-sustaining character, and high morbidity and mortality. Current treatment approaches are characterized by considerable variations, but official guidelines are lacking. To establish evidence-based guidelines and an agreement among board-certified specialists for the appropriate management of SE and CS in dogs and cats. None. A panel of 5 specialists was formed to assess and summarize evidence in the peer-reviewed literature with the aim to establish consensus clinical recommendations. Evidence from veterinary pharmacokinetic studies, basic research, and human medicine also was used to support the panel's recommendations, especially for the interventions where veterinary clinical evidence was lacking. The majority of the evidence was on the first-line management (ie, benzodiazepines and their various administration routes) in both species. Overall, there was less evidence available on the management of emergency seizure disorders in cats in contrast to dogs. Most recommendations made by the panel were supported by a combination of a moderate level of veterinary clinical evidence and pharmacokinetic data as well as studies in humans and basic research studies. Successful management of seizure emergencies should include an early, rapid, and stage-based treatment approach consisting of interventions with moderate to preferably high ACVIM recommendations; management of complications and underlying causes related to seizure emergencies should accompany antiseizure medications.

Management of status epilepticus in dogs

Background: Status epilepticus (SE) is a common neurological emergency with high mortality, and is often the first manifestation of a seizure disorder. When faced with a patient in SE (or severe cluster seizures) our priority should always be to stop the seizure activity; however, this should not distract us from assessing our seizuring patient as a whole. Neglecting to do so could lead to severe complications and could dramatically affect the patient's short‐term outcome. Management of dogs in SE requires a swift, coordinated response from all members of the veterinary team to improve chances of survival.Aim of the article: This article aims to provide a step‐by‐step guide for the management of dogs in SE with a focus on strategies to best monitor, stabilise and treat this neurological emergency.

Practical Questions About Rescue Medications for Acute Treatment of Seizure Clusters in Children and Adolescents with Epilepsy in the USA: Expanding Treatment Options to Address Unmet Needs.

Epilepsy is a common pediatric neurological condition, affecting approximately 470,000 children in the USA and having a prevalence of 0.9% in the global population of approximately 2.6 billion children. Epilepsy is associated with disruptions in several areas of a child's life, including medical burden, quality of life, cognitive outcomes, and higher risk of mortality. Additionally, some pediatric patients may experience acute seizure emergencies such as seizure clusters (also called acute repetitive seizures), which are intermittent increases in seizure activity that differ from the patient's usual seizure pattern and may occur despite daily antiseizure drug administration. Seizure clusters increase a patient's risk for status epilepticus and emergency room visits. Benzodiazepines are the main category of drugs used as acute seizure therapies for seizure clusters. This narrative review provides a practical discussion of care for pediatric patients with epilepsy and seizure clusters exploring such topics as details about the US Food and Drug Administration-approved acute seizure therapies, safety and ease of use of these medications, benefits of seizure action plans to help ensure optimal treatment, and considerations for transitioning a pediatric patient with acute seizure therapy to adult healthcare management.

Return to full baseline functionality after repeated intermittent use of midazolam nasal spray in patients with seizure clusters: Post hoc analysis of an open-label extension trial

ObjectiveTo characterize the time to return to full baseline functionality (RTFBF) in seizure cluster episodes (SCEs) treated with one or two midazolam nasal spray (MDZ-NS/Nayzilam®) doses over the course of repeated intermittent use in patients with seizure clusters (SCs). MethodsPost hoc analysis of an open-label extension trial in patients (≥12 years) with SCs (ARTEMIS-2/P261-402: NCT01529034, 2011-004109-25). Caregivers administered MDZ-NS 5 mg when patients experienced an SC; a second 5-mg dose could be given if seizures did not terminate within 10 min or recurred within 10 min–6 h. Outcomes: time to RTFBF within 24 h of MDZ-NS administration in SCEs treated with one or two doses, overall (all treated SCEs), and by number of treated SCEs for each patient over the course of the trial (Kaplan-Meier analyses). Time to RTFBF was assessed from the time of MDZ-NS administration in SCEs treated with one dose, and from the time of the second dose in SCEs treated with two doses. ResultsOne thousand nine hundred ninety-six treated SCEs (one dose: 1,201 [60.2%]; two doses: 795 [39.8%]) in 161 patients were evaluable. In SCEs treated with one or two doses, RTFBF within 24 h of MDZ-NS administration was observed in 97.2% and 94.2% of patients; the estimated median time was 1.2 and 1.3 h and stable from 1 to 45 treated SCEs. The RTFBF profile was generally similar in SCEs treated with one or two doses (30% of patients estimated to have RTFBF within 30 min, almost 50% within 1 h); the proportion of patients with RTFBF between 2 and 6h was slightly higher with one versus two doses. SignificanceIn almost all patients, RTFBF was observed within 24 h of MDZ-NS administration. The median time to RTFBF was similar in SCEs treated with one or two doses, and stable over the course of repeated intermittent use. Thus, dose (5 or 10 mg) does not seem to be a key influencer of time for RTFBF after repeated intermittent use.

Seizure clusters: diagnostic and therapeutic advances

Seizure clusters: diagnostic and therapeutic advances

Development and validation of a predictive model assessing the risk of seizure recurrence in children with neurocysticercosis

IntroductionNeurocysticercosis (NCC) is a significant factor contributing to the incidence of seizures in developing countries. While numerous studies have investigated the recurrence of seizures in NCC, their reliability is often limited. MethodsWe assessed the socio-demographic, clinical, and neuroimaging details of 161 children with seizures caused by NCC. We monitored them for seizure recurrence over a 6-month follow-up period. We divided the children into two groups: those with seizure recurrence and those without. Subsequently, we identified predictive factors associated with seizure recurrence through univariate analysis, followed by multivariate binary logistic regression. We evaluated the prognostic model for discrimination and calibration and then internally validated it using the bootstrap method. ResultsA total of 23 children experienced breakthrough seizures. In multivariate analysis, the presence of epileptiform abnormalities in electroencephalogram (EEG), more than 5 NCC lesions, the presence of perilesional edema greater than 2 cm in maximum dimension, and a cluster of seizures before presentation were significantly associated with seizure recurrence (p < 0.05). These factors were included in the final NEPC (Number of NCC lesions, Epileptiform EEG abnormality, Perilesional edema, and Cluster of seizures) score. The final model exhibited good discrimination (AUC = 89.1 %; 95 % CI=80.5–95.3 %, p < 0.001) and calibration (p = 0.54). A score of 4 appeared to be the optimal threshold for discriminating between individuals with and without seizure recurrence, with sensitivity and specificity values of 85 % and 87 %, respectively. Interrater reliability was very strong between two pediatric neurologists and strong between a pediatric neurologist and a pediatric neurology trainee resident (k = 0.92 and 0.86, respectively). ConclusionThe NEPC score demonstrates good sensitivity and specificity in predicting seizure recurrence in pediatric children with NCC.

Out-of-hospital rescue medication in dogs with emergency seizure disorders: an owner perspective.

Emergency seizure disorders such as status epilepticus and cluster seizures are unlikely to cease spontaneously while prolonged seizure activity become progressively more resistant to treatment. Early administration of rescue medication in canine epileptic patients, in particular benzodiazepines, at seizure onset by the owners can be life-saving and brain protecting. Clinical studies in dogs evaluating the use of rescue medication in hospital environment exist, however, the owner perspective has not been assessed to date. To evaluate the use of rescue medication in dogs with seizure emergencies by the owner at home. Observational study based on online surveys of owners of dogs with emergency seizure disorders. The questionnaire was answered by 1,563 dog owners, of which 761 provided complete and accurate answers suitable for analysis. Of these, 71% administered diazepam, 19% midazolam, 6% levetiracetam, 3% lorazepam, and 4% more than one rescue or other medication. Overall, the success rates based on owners' perspective for intranasal midazolam and rectal diazepam were 97 and 63%, respectively. Owners reported a compliance level of 95 and 66% for intranasal midazolam and rectal diazepam administration, respectively. Even though rectal diazepam was the most used rescue medication in this survey population, intranasal midazolam was perceived by the owners as a better option regarding effectiveness, time to seizure cessation and owner compliance.

Individualized seizure cluster prediction using machine learning and chronic ambulatory intracranial EEG.

Epilepsy patients often experience acute repetitive seizures, known as seizure clusters, which can progress to prolonged seizures or status epilepticus if left untreated. Predicting the onset of seizure clusters is crucial to enable patients to receive preventative treatments. Additionally, studying the patterns of seizure clusters can help predict the seizure type (isolated or cluster) after observing a just occurred seizure. This paper presents machine learning models that use bivariate intracranial EEG (iEEG) features to predict seizure clustering. Specifically, we utilized relative entropy (REN) as a bivariate feature to capture potential differences in brain region interactions underlying isolated and cluster seizures. We analyzed a large ambulatory iEEG dataset collected from 15 patients and spanned up to 2 years of recordings for each patient, consisting of 3341 cluster seizures (from 427 clusters) and 369 isolated seizures. The dataset's substantial number of seizures per patient enabled individualized analyses and predictions. We observed that REN was significantly different between isolated and cluster seizures in majority of the patients. Machine learning models based on REN (i) predicted whether a seizure will occur soon after a given seizure with up to 69.5% Area under the ROC Curve (AUC), and (ii) predicted if a seizure is the first one in a cluster with up to 55.3% AUC, outperforming baseline techniques. Overall, our findings could be beneficial in addressing the clinical burden associated with seizure clusters, enabling patients to receive timely treatments and improving their quality of life.

Risk factors for behavioral and psychotic dysregulation at the epilepsy monitoring unit in patients with intracranial electrodes

ObjectiveAberrant behavior in patients with epilepsy (PWE) admitted to an epilepsy monitoring unit (EMU) can endanger their safety. We sought to identify predictive factors for post-ictal behavioral dysregulation and psychosis in patients with refractory epilepsy being monitored at an EMU. MethodsRetrospective data were gathered from electronic patient files of all patients with refractory epilepsy who underwent intracranial registration at our EMU. We assessed behavioral and psychotic dysregulations by reviewing clinical notes, administered emergency medication, and reports of injuries or casualties in patients and nurses. In addition, we compared patient demographic characteristics, clinical characteristics, and antiepileptic drug (AED) profiles between patients with and without behavioral and/or psychotic dysregulation. ResultsOut of 73 admissions, 23 patients (32%) experienced behavioral dysregulation, and five patients experienced psychosis (7%). Behavioral dysregulation was only significantly associated with a previous history of interictal or postictal psychosis. Psychotic dysregulation is significantly associated with a psychiatric history, including a history of agitation or psychosis, whether or not epilepsy-related. For both types of dysregulations, there was no relation with a pre-admission frequency of seizures, clustering of seizures during monitoring, or a temporal focus of seizures. We could not report a relationship between AED use, tapering, and the occurrence of dysregulation. ConclusionWe conclude that a psychiatric history, including a history of agitation and psychosis, is related to an increased risk of behavioral and psychotic dysregulation in patients undergoing invasive seizure monitoring at the EMU.

Predicting seizure clustering in the epilepsy monitoring unit: A multivariable analysis

IntroductionSeizure clustering, is the most frequently reported adverse event in epilepsy monitoring unit (EMU) safety studies which, can also potentiate other adverse events, such as falls, status epilepticus, and increased length of stay. The purpose of this study is to determine variables associated with increased risk of seizure clustering among patients admitted to the EMU. MethodsA retrospective review of patients admitted to the EMU over a two-year period was completed. Data collected included patient demographics, types of epilepsy, seizure frequency, anti-seizure medications (ASMs) and hospital and EMU course including incidence of seizure clustering. ResultsTwo hundred seven patients were included in our study; of these, ninety patients experienced two or more seizures in a 24-hour period (24SC), and 68 patients experienced two or more seizures in a 4-hour period (4SC). Logistic regression analysis associated the absence of long-acting ASM with increased clustering within the 4SC group (p = 0.038). For every additional ASM taken by a patient at home, the odds of seizure clustering increased by 81% in the 4SC group (p = 0.009) and by 61% in the 24SC group (p = 0.022). In addition, patients with a diagnosis of temporal lobe epilepsy had some association with clustering in the 24SC group (p = 0.061). ConclusionOur data showed that long-acting ASMs can be protective against seizure clustering. Furthermore, patients with temporal lobe epilepsy, and those on increased numbers of ASMs, were more likely to experience seizure clustering when undergoing medication withdrawal during an EMU evaluation.

On-demand low-frequency stimulation for seizure control: efficacy and behavioural implications.

Mesial temporal lobe epilepsy (MTLE), the most common form of focal epilepsy in adults, is often refractory to medication and associated with hippocampal sclerosis. Deep brain stimulation represents an alternative treatment option for drug-resistant patients who are ineligible for resective brain surgery. In clinical practice, closed-loop stimulation at high frequencies is applied to interrupt ongoing seizures, yet has (i) a high incidence of false detections; (ii) the drawback of delayed seizure-suppressive intervention; and (iii) limited success in sclerotic tissue. As an alternative, low-frequency stimulation (LFS) has been explored recently in patients with focal epilepsies. In preclinical epilepsy models, hippocampal LFS successfully prevented seizures when applied continuously. Since it would be advantageous to reduce the stimulation load, we developed a protocol for on-demand LFS. Given the importance of the hippocampus for navigation and memory, we investigated potential consequences of LFS on hippocampal function. To this end, we used the intrahippocampal kainate mouse model, which recapitulates the key features of MTLE, including spontaneous seizure activity and hippocampal sclerosis. Specifically, our online detection algorithm monitored epileptiform activity in hippocampal local field potential recordings and identified short epileptiform bursts preceding focal seizure clusters, triggering hippocampal LFS to stabilize the network state. To probe behavioural performance, we tested the acute influence of LFS on anxiety-like behaviour in the light-dark box test, spatial and non-spatial memory in the object location memory and novel object recognition test, as well as spatial navigation and long-term memory in the Barnes maze. On-demand LFS was almost as effective as continuous LFS in preventing focal seizure clusters but with a significantly lower stimulation load. When we compared the behavioural performance of chronically epileptic mice to healthy controls, we found that both groups were equally mobile, but epileptic mice displayed an increased anxiety level, altered spatial learning strategy and impaired memory performance. Most importantly, with the application of hippocampal LFS before behavioural training and test sessions, we could rule out deleterious effects on cognition and even show an alleviation of deficits in long-term memory recall in chronically epileptic mice. Taken together, our findings may provide a promising alternative to current therapies, overcoming some of their major limitations, and inspire further investigation of LFS for seizure control in focal epilepsy syndromes.

Duration of constant rate infusion with diazepam or propofol for canine cluster seizures and status epilepticus.

Constant rate infusion (CRI) of benzodiazepines or propofol (PPF) is a therapeutic option for cluster seizures (CS) and status epilepticus (SE) in canine patients non-responding to first-line benzodiazepines or non-anesthetics. However, specific indications for optimal duration of CRI are lacking. The aim of this study was to determine the effect of duration of anesthetic CRI on outcome and length of hospital stay in dogs with refractory seizure activity of different etiology. Open-label non-randomized clinical trial. Seventy-three client-owned dogs were enrolled. Two groups [experimental (EXP) vs. control (CTRL)] were compared. The EXP group received diazepam (DZP) or PPF CRI for 12 h (±1 h) and the CTRL group received DZP or PPF CRI for 24 h (±1 h) in addition to a standardized emergency treatment protocol identical for both study groups. The historical control group was made up of a population of dogs already reported in a previously published paper by the same authors. Favorable outcome was defined as seizure cessation after CRI, no seizure recurrence, and clinical recovery. Poor outcome was defined as seizure recurrence, death in hospital or no return to acceptable clinical baseline. Univariate statistical analysis was performed. The study sample was 73 dogs: 45 (62%) received DZP CRI and 28 (38%) received PPF CRI. The EXP group was 39 dogs (25 DZP CRI and 14 PPF CRI) and the CTRL group 34 dogs (20 DZP CRI and 14 PPF CRI). We found no statistically significant difference in outcomes between the groups. The median length of stay was 56 h (IQR, 40-78) for the ALL EXP group and 58.5 h (IQR, 48-74.5) for the ALL CTRL group (p = 0.8). Even though a shorter DZP or PPF CRI duration was not associated with a worse outcome, the study failed to identify a clear superiority of shorter CRI duration on outcome or length of hospital stay in dogs with refractory seizure activity of different etiology.

CPEB4 - CLOCK crosstalk during temporal lobe epilepsy.

Post-transcriptional mechanisms are increasingly recognized as important contributors to the formation of hyperexcitable networks in epilepsy. Messenger RNA (mRNA) polyadenylation is a key regulatory mechanism governing protein expression by enhancing mRNA stability and translation. Previous studies have shown large-scale changes in mRNA polyadenylation in the hippocampus of mice during epilepsy development. The cytoplasmic polyadenylation element-binding protein CPEB4 was found to drive epilepsy-induced poly(A) tail changes and mice lacking CPEB4 develop a more severe seizure and epilepsy phenotype. The mechanisms controlling CPEB4 function and the downstream pathways that influence the recurrence of spontaneous seizures in epilepsy remain poorly understood. Status epilepticus was induced in wild-type and CPEB4-deficient male mice via an intra-amygdala microinjection of kainic acid. CLOCK binding to the CPEB4 promoter was analyzed via Chromatin immunoprecipitation assay and melatonin levels via High-Performance Liquid Chromatography in plasma. Here we show increased binding of CLOCK to recognition sites in the CPEB4 promoter region during status epilepticus in mice and increased Cpeb4 mRNA levels in N2A cells overexpressing CLOCK. Bioinformatic analysis of CPEB4-dependent genes undergoing changes in their poly(A) tail during epilepsy found that genes involved in the regulation of circadian rhythms are particularly enriched. Clock transcripts displayed a longer poly(A) tail length in the hippocampus of mice post-status epilepticus and during epilepsy. Moreover, CLOCK expression was increased in the hippocampus in mice post-status epilepticus and during epilepsy, and in resected hippocampus and cortex of patients with drug-resistant temporal lobe epilepsy. Further, CPEB4 is required for CLOCK expression after status epilepticus, with lower levels in CPEB4-deficient compared to wild-type mice. Last, CPEB4-deficient mice showed altered circadian function, including altered melatonin blood levels and altered clustering of spontaneous seizures during the day. Our results reveal a new positive transcriptional-translational feedback loop (TTFL) involving CPEB4 and CLOCK, which may contribute to the regulation of the sleep-wake cycle during epilepsy.